This morning, I was getting repeated "the credentials that were used to connect to 'computername' did not work" error messages when trying to log into my PC at the office remotely from my work laptop, although I could log in to all other systems just fine.
My account is a single sign-on Microsoft account managed by my employer. Both the laptop and the desktop are running Windows 10.
Eventually, I figured out that it was only certain PCs I could not remote desktop into - using the exact same credentials on other PCs on the same physical network as my work desktop let me in, and once I was remoted in to another PC, from that other PC I could then make another remote desktop connection to my work desktop using the exact same credentials again. So it looks like the trouble is actually with the laptop I am making the remote desktop connection from, not with my account or with the computer I am trying to remote desktop into.
So far, I have found two remote PCs that this laptop cannot remote into that other PCs can remote into. Unfortunately, one of the two is my work desktop which I frequently log into while working remotely.
I thought it might be a certificate issue, so I followed the instructions to "forget" the certificate from this answer, but it still gives me the same error when trying to remote into my work desktop directly from my work laptop.